For example, JP-A-2007-278084 discloses a power-driven pump apparatus that is used for a brake fluid pressure control apparatus.
The pump apparatus disclosed in JP-A-2007-278084 has a well-known internal gear pump having combined an inner rotor (external gear) and an outer rotor (internal gear) and has two sets of pumps that are provided on the same axial line and are driven by the same rotary shaft. Also, a seal member, which seals an outer periphery of a driving rotary shaft to hydraulically partition the two sets of pumps, is provided between the two sets of pumps.
Also, a housing that accommodates the seal member therein is provided with a partition wall that prevents the seal member from moving toward one pump. A bearing is provided between the other pump and the seal member and prevents the seal member from moving toward the other pump. Accordingly, the partition wall is only provided between a seal member accommodation chamber and the one pump, and a rotary shaft for driving a pump passes through a shaft hole that is formed in the partition wall.
In the meantime, an end face of a pump accommodation chamber provided in the housing is formed with a liquid chamber (suction pump or discharge pump) communicating with a chamber (pump chamber) of the pump and the liquid chamber, and the seal member accommodation chamber are separated by the partition wall.